In some printing systems, print agent may be dissolved into a solvent to form a print solution which may be used as ink in the printing system to be printed onto a substrate (such as a sheet paper).
In some examples, the print agent may be stored in a canister or receptacle until it is to be used. When a print agent canister nears an empty state, it may be replaced by a new print agent canister. However, some print agent may be left inside the canister and may be disposed of and wasted.